Plug-handling mechanism for seamless tube mills



M. S. GETTIG April 21, 1953 PLUG-HANDLING MECHANISM FOR SEAMLESS TUBEMILLS 3 Sheets-Sheet l Filed March 20, 1946 ImcNl/ INVENTOR Ill JW/vwvmi fwn April 2l, 1953 M. s. GETTIG 2,635,492

PLUG-HANDLING MECHANISM FOR SEAMLESS TUBE MILLS Filed March 20, 1946 3Sheets-Sheet 2 INVENTOR Maf/075 6927@ A, mi?,

April 21, 1953 M. s. GETTIG 2,635,492

PLUG-HANDLING MECHANISM FOR SEAMLESS TUBE MILLS Filed March 20, 1946 5Sheets-Sheet 5 fig. s.

IINVENTOR Mr/fn S. GIS/77g ma m I W Patented Apr. 2l, 1953 GFFICEPLUG-HANDLING MECHANISM FOR SE-AMLESS nlTUBE MILLS Y Martin S.Gettig,v"Youngstown, Ohio Application March 20, 1946, Serial N o. 655,737

' 2V Claims.

This invention relates to seamless tube mills and, in particular, to theso-called two-high or .plug mill in which pierced billets are rolledafter being expanded and drawn out in a Mannesman mill, to bring them toiinal shape, size and wall thickness. Specifically, the inventionconcerns fa mechanism for placing a plug on the end of the mandrel andremoving it therefrom and to a roll vfor supporting the mandrel to keepit properly centered relative to the pass between the mill rolls. Y

Mechanism for handling the plug used on a two-high pipe mill has beenproposed heretofore but has not come into actual use for variousreasons, .and the manual handling of the plug has continued to be theregular commercial practice. I have invented a novel form ofplug-handling mechanism characterized by simplicity of construction andease of operation, capable of satisfactorily handling plugs andeliminating fthe-strenuous labor involved in doing this work manually.In a preferred embodiment, my plughandling mechanism Y comprises anelongated member having a socket in one end adapted to receive a pinprojecting from the plug. This plug-holding member is suspended onparallel pairs of links spaced therealong for movement from a positionadjacentV the end of the mandrel to a position spaced and offsettherefrom. Powler means such as a fluid-pressure cylinder and piston areprovided for shifting the member from one position to the' other. Myinvention also lcontemplates novel means for supporting the mandrel oi aplug mill to center it properly in lthe roll pass and aline the mandrelwith the axis of the-plug-handlingv mechanism.. This means includes asupporting roll disposed below the mandrel and mounted for movementtoward and away from it. Means for operating the support roll include atoggle linkage and power means for extending or shortening it.Appropriate stops for the power means may be adjust ed to control themovement of the roll for various sizes of mandrels and variousthicknesses of pipe wall. I also provide means for cooling the plugwhile in retractedposition, comprising a lspray ring movable from anout-of-the-way position into cooperative relation to the plug.

A complete understanding of the invention may be gained from thefollowing detailed description which refers to the accompanying drawingsillustrating the preferred embodiment.

In the drawings, v f .1 Figure 1 is a central vertical section throughplus mill. .harina .the inveniien, ,incerprated therein;

.l showing a modified plug-handling apparatus Aincluding a movable sprayring; and

Figure 4 is a partial section taken along the plane of line IV-IV ofFigure 3.

Referring now in detail to the drawings, a twohigh or plug mill forfinishing seamless tubes vcomprises housings I0 and II having windowsvtherein adapted to accommodate chucks I2 and I3 in which grooved upperand lower rolls I4 and I5 are journaled. The rolls have grooves IGtherein defining circular passes. The upper roll I4 may be adjustedvertically by .screws Il and the lower roll by screws I8. The chucks I2of the upper roll are held against the screws Il I9by counterbalancemechanism indicated at A pipe blank passing between the rolls isdirected onto a mandrel 20 by guides 2I. The end of the mandrel remotefrom the mill is fixed, being secured to side frames 22 extending fromthe housings Il) and II. When the pipe has passed through the mill, therolls thereof tare opened, as shown in the drawings, to permit the pipeto be run back through the mill by rolls .23.. These rolls are opened upwhen the pipe vadvances onto the mandrel and are closed onto the pipe toreturn it back through the mill.

The mechanism for opening and closing the rolls I4 and I5 includes wedgebars 24 cooperating with split blocks 25 between the screws and vthebearing chucks. The wedge bars are operated by fluid-pressure cylindersand pistons 26 vmounted on brackets 2l secured to the housing I I.

The mill construction described above is conventional except that thewedge bars 25 have heretofore been used only for the upper roll.

As clearly shown in Figure l, the free end of the mandrel 20 extendsthrough tubular guides 28 and terminates in a cap 29. This cap isdrilled to receive one end of a pin 38 extending centrally through aplug 3|.' The mechanism of my invention for removing the plug from themandrel to permit a tube which has been rolled to be backed ofi from themandrel comprises a bar 32 disposed parallel to the mandrel and movablefrom a position adjacent and in alinement therewith to a retractedoffset position, as shown in chain lines in Figure 1. The end of the bar32 adjacent the mandrel has a socket adaptedto accommodate vthe forwardend of the pin` 3i). The bar 32 isv supported by pairs of vparallellinks 33 so that it remains horizontal when retracted. The links 33 arepivoted to a supporting bracket 34. The bracket 34 is carried bycrossbars 35 extending between the housings l0 and Il. The bracket 34may be adjusted along the crossbars to bring the axis of the bar 32 inthe median plane through any one of the several grooves in the rolls.The links are pivoted to the bar 32 at points spaced along the lengththereof. A huid-pressure cylinder' and piston 36 is provided forswinging the bar 32 from its position adjacent the mandrel to retractedposition. The cylinder is pivoted to a downward extension 34a on thebracket 34. The piston rod is pivoted to the pair of links 33 nearer tothe mill rolls.

The plug pin 3| has a reduced neck 3|a adjacent its forward end. A latchmember 31 piv`` oted on the bar 32 is adapted to engage the reduced neckupon entering a hole intersecting the socket. A fluid-pressure cylinderand piston I8 is trunnioned on the bar 32 and is pivoted to the latchmember 31 for swinging it from the position shown in Figure l to aretracted position in which it frees the mandrel pin. Fluid underpressure is admitted to and exhausted from the ends of the cylinder by asuitable valve through flexible hose connections.

It will be apparent from the foregoing that the bar 32 is normally heldin retracted position by the cylinder and piston 36. After the pipe haspaed through the mill and onto the mandrel, the bar 32 is permitted toswing (which it may do by gravity) down into position in alinement withthe mandrel whereupon the plug pin enters the socket in the bar and issecured therein by latch member 31. The bar 32 is then retracted and thepipe is run back oif of the mandrel. When the pipe has been withdrawnfrom the mill, the bar 32 is again permitted to swing down to return theplug to the mandrel. It will be understood that the plug automaticallyreturns to its position on the end of the mandrel and is left there onretraction of the bar 32 after the latch 31 has been released.

I may provide nozzles in suitable positions to discharge a spray ofcooling water onto the plug when held by the bar 32 in the retractedposition of the latter. A suitable baille disposed under the plug willprevent the cooling water from striking the pipe as it is being returnedfrom the mill.

Since the mandrel 20 is fixed only at the end thereof remote from themill, the end to which the plug is applied would tend to ride on thebottom roll |5. In order to center the mandrel and the plug thereonrelative to the roll pass, I provide a support roll 40. This roll isjournaled in bearings mounted on a base 4|. The base is mounted on arocker arm 42 and is adjustable transversely thereof. The rocker arm 42is fixed on a rock shaft 43 Journaled in the roll housings. The rockshaft is actuated by a bell crank 44 through a link 45 and an arm 46rigid with the shaft 43. The bell crank is pivoted to a link 41 which ispivoted to a xed bearing 43 carried on one of the housings.

A fluid-pressure cylinder and piston 49 trunnioned on a frame member 50has a piston rod extending therethrough, one end of which is pivoted tothe bell crank 44. The other end has a bumper adapted to engage anadjustable stop 52. A fluid-pressure cylinder and piston 5I is alsotrunnioned on the frame member 50 and has a piston rod 54 extendingtherethrough,

one end of which is pivoted to the bell crank and the link 41. The otherend is provided with a bumper adapted to engage an adjustable stop 55.

When the roll 40 is in its illustrated position, the mandrel 20 isproperly centered relative to the roll pass for entry of a tubularblank. When a blank has entered the mill, the cylinder 53 is operated tolower the roll 40 by a distance approximately equal to the wallthickness of the pipe being made so that, after the leading end of thepipe passes the roll 40, the latter will engage the exterior thereof andcontinue to support the mandrel in properly centered position after thetrailing end of the pipe has passed through the mill. This lowering ofthe roll 40 is accomplished by operating the cylinder 53 to shift itspiston rod to the left until it engages stop 55. It will be apparentthat this causes angular movement of the bell crank 44 which through thelink and arm 46 causes counterclockwise rotation of the rock shaft 43.

When the pipe is stripped from the mandrel. the cylinder 53 is operatedto shift its piston rod in the other direction after the leading end ofthe pipe passes beyond the roll 40 and before 'it passes out of themill. As a result, the mandrel is again supported in properly centeredposition relative to the roll pass. The cylinder 43 is operated so thatits piston rod is normally urged against the stop 52. If the mandrel 2Bis replaced by one of different size. as for the purpose of rollinglarger or smaller pipe, the stop 52 is adjusted so that when it isengaged by the piston rod 5|, the roll 4U will be at the proper positionfrom the axis of the roll pass to support the mandrel prior to entry ofthe pipe length. A similar adjustment of the stop 55 may be made in caseof a change in the wall thickness of the pipe being rolled,

Figures 3 and 4 illustrate a slightly modified construction includingmeans for spraying jets of cooling liquid on the plug while it issupported by the bar 32 in retracted, offset position. Certain oftheelements of the apparatus shown in Figure 3 are the same as those shownin Figures 1 and 2 and are designated by the same reference numerals. Asclearly shown in Figures 3 and 4, the bracket 34 supported by the crossbars 35 has a downward extension 34h which provides a pivotal mountingnot only for the cylinder and piston 35 but a similar cylinder andpiston 58. The piston rod of this latter cylinder is pivoted to a lever51. The lever is pivoted to the bracket 34 at 58 and is vactuated fromthe position in which it is shown in solid lines in Figure 3 to thechain-line position, by extension of the piston rod of cylinder 53.

A pipe ring 59 has a stud 60 welded thereto. The stud is adjustablydisposed within a sleeve 6| forming part of the lever 51. The ring 59may thus be secured to the lever in proper relation thereto by a setscrew 62 threaded through a. tapped hole in the sleeve and engaging thestud 60. A lateral connection 63 from the pipe ring 53 is adapted toreceive a flexible hose 64 extending to a suitable source of coolingwater. The pipe ring 53 has holes 65 spaced circumferentially around theinterior thereof whereby a plurality of cooling jets may be dischargedonto the plug 3|. As illustrated, the pipe ring is of sufilcient insidediameter to embrace the plug with a substantial clearance therebetween.While a billet is being rolled in the mill, the lever Bland pipe ring5l. of course, are held in their chain-line position by suitablyactuating the cylinder 56. When the plug 3| has been removed andretracted to the position shown in solid lines in Figure 3 by operationof the cylinder 36, the cylinder 56 is operated to bring the pipe ring59 into cooperative relation with the plug carried on the bar 32. Thecooling water ls then turned on and the jets impinging on the plugquickly cool it, removing the heat picked up thereby during passage ofthe billet into the mill. When the rolled billet has been withdrawn andis ready for a second pass, the cylinder 56 is again actuated to swingthe lever 51 and pipe ring 59 to their outof-theway position shown inchain lines after which the cylinder 36 is operated to restore c theplug to its working position on the end of the mandrel 20.

It will be apparent from the foregoing that the invention providessimple but effective means for handling plugs to and from the mandrel ofa plug mill and for supporting the mandrel in properly centeredposition. All necessary movements of the parts in regular operation areeffected by power means which can be easily controlled from any desiredpoint. The strenuous labor involved in manual handling of the plugs isentirely eliminated. Normal operation of the mill in the customarymanner is not interfered with.

The mandrel is properly supported centrally of the pass through the millat all times and the supporting roll therefor is lowered sufficientlyafter the entry of a billet to accommodate the W-all thickness of thepipe into which the billet is converted by the rolling operation.Provision lis also made for cooling the plugs while out of i' the mill,the cooling means being movable into cooperative relation with the plugwhile it is supported in retracted position.

Although I have illustrated and described but a preferred embodiment ofthe invention, it will be recognized that changes in the details ofconstruction disclosed may be made without departing from the spirit ofthe invention or the scope of the appended claims.

I claim:

1. Apparatus for applying a plug to the mandrel of a plug mill andremoving it therefrom comprising a plug-holding member, a supportdisposed at an elevation above the elevation of the plug when inposition on the mandrel, mounting means carrying the plug-holdingmember, the mounting means comprising two parallel links respectivelypivoted at their upper ends to the support about parallel axes dening -agenerally horizontal plane and respectively pivo-ted at their lower endsto the plug-holding member about parallel axes dening a generallyhorizontal plane land spaced apart ya distance substantially equal tothe distance which the rst mentioned parallel axes are spaced apart, aspray ring carrier also pivoted at its upper end to the support about apivot whose axis is substantially parallel with said rst mentionedparallel axes and carrying a spray ring movable about the axis of thelast mentioned pivot into and out of position generally surrounding aplug lmaintained by the plug-holding member at an elevation above thesecond mentioned elevation for spraying cooling fluid onto the plug.

2. A mandrel and removable plug mechanism comprising a mandrel, a, xedsupport supporting the mandrel adjacent one end, the mandrel beingadapted to receive on its other end a plug tointernally shape a tubularblank passed over the plug onto the mandrel and which plug is removablefrom the mandrel when the blank is to be withdrawn from the mandrel, aplug-holding member, a second support in fixed position relatively tothe xed mandrel support, a link pivotally connected to the plug-holdingmember and to the second support carrying the plug-holding member forswinging movement between a position relatively close to said other endof the mandrel and a position relatively remote therefrom, meanscooperating with the plug-holding member and the second support formaintaining the laxis of the plug parallel to the axis of the mandrelduring said swinging movement, said link when in its rst mentionedposition being substantially perpendicular to the axis of the mandreland of such length that the plug-holding member is disposed in said axisand moving the plug-holding member substantially in the axis of themandrel to apply the plug to the lmandrel and remove it therefrom, andmeans for swinging the plug-holding member between its rst mentioned andsecond mentioned positions.

MARTIN S. GETTIG.

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